Cyber Resilience

CVE-2021-33478

Medium

Published: 22 July 2021

Published
22 July 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.8 CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0013 32.5th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33478 is a medium-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Cisco Ip Phone 8800 Firmware. Its CVSS base score is 6.8 (Medium).

Operationally, ranked at the 32.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

The TrustZone implementation in certain Broadcom MediaxChange firmware could allow an unauthenticated, physically proximate attacker to achieve arbitrary code execution in the TrustZone Trusted Execution Environment (TEE) of an affected device. This, for example, affects certain Cisco IP Phone and…

more

Wireless IP Phone products before 2021-07-07. Exploitation is possible only when the attacker can disassemble the device in order to control the voltage/current for chip pins.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cisco
ip phone 8800 firmware
≤ 14.0\(1\)
cisco
ip phone 8800 series with multiplatform firmware
≤ 11.3\(4\)
cisco
ip phone 8811 firmware
≤ 14.0\(1\)
cisco
ip phone 8811 with multiplatform firmware
≤ 11.3\(4\)
cisco
ip phone 8841 firmware
≤ 14.0\(1\)
cisco
ip phone 8841 with multiplatform firmware
≤ 11.3\(4\)
cisco
ip phone 8845 firmware
≤ 14.0\(1\)
cisco
ip phone 8845 with multiplatform firmware
≤ 11.3\(4\)
cisco
ip phone 8851 firmware
≤ 14.0\(1\)
cisco
ip phone 8851 with multiplatform firmware
≤ 11.3\(4\)
+5 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References